core: fix default trie cache limit (#17860)

core/blockchain.go

@@ -140,7 +140,7 @@ type BlockChain struct {
 func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, chainConfig *params.ChainConfig, engine consensus.Engine, vmConfig vm.Config, shouldPreserve func(block *types.Block) bool) (*BlockChain, error) {
 	if cacheConfig == nil {
 		cacheConfig = &CacheConfig{
-			TrieNodeLimit: 256 * 1024 * 1024,
+			TrieNodeLimit: 256,
 			TrieTimeLimit: 5 * time.Minute,
 		}
 	}